About None Start Events
A none start event is not capable of starting a process instance. A none start event represents the beginning of the flow in a BPMN callable process, which is called by a BPMN call activity.
If you implement a call activity, you must use a none start event in the targeted BPMN callable process. A none start event is not associated with a receive document. As other none events (start and end), it has no generated wrapper service.
Tip: You can convert a None Start Event to a Message Start Event by dragging a document from the Registry Explorer, Package Navigator, or Search view, and dropping it onto a None Start Event. The Message Start Event is automatically associated with the document dragged to the step.